U.S. patent application number 10/790732 was filed with the patent office on 2005-07-07 for wireless earphone.
Invention is credited to Lin, Yen Hsi.
Application Number | 20050148374 10/790732 |
Document ID | / |
Family ID | 34709566 |
Filed Date | 2005-07-07 |
United States Patent
Application |
20050148374 |
Kind Code |
A1 |
Lin, Yen Hsi |
July 7, 2005 |
Wireless earphone
Abstract
A wireless earphone communicates with a mobile phone by wireless
and comprises a microprocessor, a feedback-type charging circuit
and a rechargeable battery therein. The microprocessor output
control signals to control the feedback-type charging circuit for
charging the rechargeable battery; the feedback-type charging
circuit also feeds back the charging current and charging states of
the rechargeable battery to the microprocessor. Therefore, the
microprocessor may change the charging current depending on the
states of the rechargeable battery. By changing the voltage of the
control signals, the charging current of the feedback-type charging
circuit can be adjusted by the microprocessor. The present
invention provides a charging design by software control to reduce
the production cost of wireless earphone.
Inventors: |
Lin, Yen Hsi; (Hsintien
City, TW) |
Correspondence
Address: |
ROSENBERG, KLEIN & LEE
3458 ELLICOTT CENTER DRIVE-SUITE 101
ELLICOTT CITY
MD
21043
US
|
Family ID: |
34709566 |
Appl. No.: |
10/790732 |
Filed: |
March 3, 2004 |
Current U.S.
Class: |
455/575.2 ;
455/41.3 |
Current CPC
Class: |
H02J 7/007182 20200101;
H04M 1/6041 20130101; H02J 7/0072 20130101; H02J 7/00714
20200101 |
Class at
Publication: |
455/575.2 ;
455/041.3 |
International
Class: |
H02J 007/24; H02J
007/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 6, 2004 |
TW |
93100275 |
Claims
What is claimed is:
1. A wireless earphone communicating with a mobile phone by
wireless signals, the wireless earphone comprising: a communication
unit receiving and emitting the wireless signals; a rechargeable
battery; a feedback-type charging circuit providing a charging
current for the rechargeable battery and feeding back charging
states of the rechargeable battery; and a microprocessor
controlling operations of the communicating unit and outputting a
control signal for adjusting the charging current of the
feedback-type charging circuit.
2. The wireless earphone as in claim 1, wherein the communication
unit comprises: a microphone; a speaker; and a wireless
receiving/transmitting module receiving signals from the microphone
and transmitting signals wirelessly to a mobile phone, wherein
wireless signals transmitted by the mobile phones are also received
by the wireless receiving/transmitting module and output by the
speaker.
3. The wireless earphone as in claim 1, wherein the wireless
receiving/transmitting module is a Bluetooth.TM. module.
4. The wireless earphone as in claim 1, wherein the feedback-type
charging circuit comprises: a charging current control circuit
receiving an input direct current and the control signals, wherein
the charging current control circuit also outputs the charging
current and changes the charging current value according to the
control signals; a first detecting circuit detecting the charging
current of the charging current control circuit; and a second
detecting circuit detecting the voltage value of the rechargeable
battery; wherein the microprocessor detects the voltage value of
the rechargeable battery by the second detecting circuit and the
current value of the rechargeable battery by the first detecting
circuit and the microprocessor hence changes the charging current
and charges the rechargeable battery.
5. The wireless earphone as in claim 4, wherein the charging
current control circuit comprises: a first MOS transistor having a
third terminal for outputting the charging current; a second MOS
transistor having a first terminal connected to a second terminal
of the first MOS transistor, the control signals being input to a
second terminal of the second MOS transistor; a resistor having two
terminals connected to the first terminal and the second terminal
of the first MOS transistor, respectively; and a capacitor having
two terminals connected to the first terminal of the first MOS
transistor and the second terminal of the second MOS
transistor.
6. The wireless earphone as in claim 4, further comprising a
voltage transforming circuit connected to the output terminal of
the charging current control circuit.
7. The wireless earphone as in claim 1, further comprising a
buzzer, wherein a tone of the buzzer is controlled by a buzzer
control circuit connected between the microprocessor and the
buzzer.
8. A charging circuit of a wireless earphone receiving control
signals output from a microprocessor and charging a rechargeable
battery, the charging circuit comprising: a charging current
control circuit receiving an input direct current and the control
signals, wherein the charging current control circuit also outputs
the charging current and changes a charging current value according
to the control signals; a first detecting circuit detecting the
charging current of the charging current control circuit; and a
second detecting circuit detecting a voltage value of the
rechargeable battery; wherein the microprocessor detects the
voltage value of the rechargeable battery by the second detecting
circuit and the current value of the rechargeable battery by the
first detecting circuit, and the microprocessor changes the
charging current for charging the rechargeable battery.
9. The charging circuit of the wireless earphone as in claim 8,
wherein the charging current control circuit comprises: a first MOS
transistor having a third terminal for outputting the charging
current; a second MOS transistor having a first terminal connected
to a second terminal of the first MOS transistor, wherein the
control signals are input into a second terminal of the second MOS
transistor; a resistor having two terminals connected to the first
terminal and the second terminal of the first MOS transistor,
respectively; and a capacitor having two terminals connected to the
first terminal of the first MOS transistor and the second terminal
of the second MOS transistor.
10. The charging circuit of the wireless earphone as in claim 8,
further comprising a voltage transforming circuit connected to the
output terminal of the charging current control circuit.
11. A method for charging a wireless earphone, the wireless
earphone having a microprocessor, a feedback-type charging circuit
and a charging circuit set therein, wherein the microprocessor
controls the feedback-type charging circuit to charge a
rechargeable battery, the method having steps as follows: detecting
a voltage level of the rechargeable battery with the feedback-type
charging circuit; comparing a difference between the voltage level
of the rechargeable battery and a preset value by the
microprocessor; and adjusting a charging current of the
feedback-type charging circuit by the microprocessor.
12. The method for charging the wireless earphone as in claim 11,
further comprising a step of detecting the charging current for the
microprocessor by the feedback-type charging circuit.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is a wireless earphone, especially
relates to a wireless earphone that can charge rechargeable
batteries with an interior charging circuit.
[0003] 2. Description of Related Art
[0004] Wireless earphones used with mobile telephones mainly use
the Bluetooth.TM. wireless communication technique. Therefore, the
above-mentioned earphone is also referred to a Bluetooth.TM.
earphone. Rechargeable batteries are used as power sources for
prior art Bluetooth.TM. earphones, and the rechargeable batteries
are usually set inside the Bluetooth.TM. earphones. FIG. 1 shows a
schematic structure diagram of the Bluetooth T earphone 70. A
rechargeable battery 73 is charged by supplying a direct current to
an input terminal of a charging IC 71, and the charging IC 71 will
provide the electricity for the rechargeable battery 73. After the
rechargeable battery 73 is charged, it will provide electric power
for a Bluetooth T wireless communication circuit 75.
[0005] The structure shown in FIG. 1 uses a hardware which provides
charging functions. A charging IC 73 (ex. TI BQ24010) is the
above-mentioned hardware and integrates many other functions inside
the earphone. The cost of using the charging IC 73 is more
expensive than using simple charging circuit. Therefore, replacing
charging IC 73 with simple charging circuit and using a control
unit to control charging functions for charging circuit may reduce
the production cost thereof.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a
cheaper wireless earphone.
[0007] Another object of the present invention is to provide a
wireless earphone and adjust the charging current correctly by a
feedback function. By this way, the voltage of the rechargeable
battery is steadier.
[0008] Still another object of the present invention is to provide
a wireless earphone and a buzzer for outputting a louder voice.
Users will be warned of the operating states of the earphone.
[0009] To achieve above-mentioned objects, the present invention
provides a wireless earphone connected wirelessly with a mobile
phone. The wireless earphone comprises a communicating unit, a
rechargeable battery, a charging circuit with feedback function,
and a microprocessor. The communicating unit is used for receiving
and emitting communication signals; the charging circuit provides
current for charging the rechargeable battery and feedbacks states
of the rechargeable battery; and the microprocessor controls the
communication unit and outputs a control signal for adjusting the
charging current of the charging circuit by identifying the states
of the rechargeable battery.
[0010] To achieve above-mentioned objects, the present invention
provides a charging circuit for receiving the control signals
output from the microprocessor and charging a rechargeable battery.
The charging circuit comprises: a charging current control circuit
receiving input direct current and control signals, a first
detecting circuit detecting the charging current of the charging
current control circuit, and a second detecting circuit detecting
the voltage value of the rechargeable battery. The charging current
control circuit also outputs charging current and changes the
current values according to the control signals. The microprocessor
may detect the voltage value of the rechargeable battery by the
second detecting circuit and the current value of the rechargeable
battery by the first detecting circuit. Hence, the microprocessor
can change the charging current and charge the rechargeable
battery.
[0011] To achieve above-mentioned objects, the present invention
provides a method for charging wireless earphones. A
microprocessor, a feedback-type charging circuit and a charging
circuit are set inside a wireless earphone, in which the
microprocessor controls the feedback-type charging circuit for
charging a rechargeable battery. The method for charging provides:
detecting the voltage level of the rechargeable battery by the
feedback-type charging circuit; comparing the difference between
the voltage level of the rechargeable battery and its preset value;
and adjusting the charging current of the feedback-type charging
circuit by the microprocessor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The various objects and advantages of the present invention
will be more readily understood from the following detailed
description when read in conjunction with the appended drawing, in
which:
[0013] FIG. 1 shows a schematic diagram of a circuit structure
inside a prior art wireless earphone;
[0014] FIG. 2 shows a system block diagram of a preferred
embodiment of the present invention;
[0015] FIG. 3 shows a diagram of a buzzer control circuit of the
present invention;
[0016] FIG. 4 shows a feedback-type charging circuit diagram of a
preferred embodiment of the present invention;
[0017] FIG. 5 shows a charging voltage wave diagram of a
rechargeable battery in the present invention; and
[0018] FIG. 6 shows a state diagram of the rechargeable battery of
the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] Reference is made to FIG. 2, which shows a system block
diagram of the present invention. An internal structure of a
wireless earphone in the present invention comprises a
microprocessor 10, a communication unit 12, a feedback-type
charging circuit 14, a rechargeable battery 20, a buzzer control
circuit 16 and a buzzer 22.
[0020] The communication unit 12 can communicate with mobile phones
by transferring wireless signals; the communication unit 12 has the
same internal structure with prior art wireless earphones, which
transfers wireless signals by a wireless receiving/transmitting
module 121. Therefore, a microphone 123 can receive audio signals,
and the audio signals will be processed by a microphone amplifier
122. After that, the wireless receiving/transmitting module will
transmit the audio signals transferred by the microprocessor 10.
The microprocessor 10 may also decode the wireless signals received
by the wireless receiving/transmitting module 121 into audio
signals; through an earphone amplifier 124, the audio signals are
output by a speaker 125. Wireless receiving/transmitting module 121
is preferably a Bluetooth.TM. module.
[0021] The present invention provides a buzzer control circuit 16,
which controls the tone ring of the buzzer 22. Reference is made to
FIG. 3, which shows a buzzer control circuit diagram. The
microprocessor 10 outputs signals to the NMOS transistor Q3 via a
resistor R2 for controlling on/off states of the NMOS transistor
Q3, and output states of amplifiers (U5A and U5B) will be changed
thus. Audio signals are output from amplifiers U5A and U5B and
transmitted to two terminals of the buzzer 22. Hence, depending on
the states (power on/off, dead battery or incoming call) of the
wireless earphone, the microprocessor 10 can output different tone
signals to drive the buzzer 22.
[0022] The present invention replaces prior art charging IC by the
feedback-type charging circuit 14. The feedback-type charging
circuit 14 is controlled by a control signals (AUXDAC) output from
the microprocessor 10 and is used to feedback charging current and
voltage states of the rechargeable battery to the microprocessor
10. If the voltage of the rechargeable battery 20 is abnormal, the
microprocessor 10 will change the charging current. Further, the
microprocessor 10 in this embodiment utilizes software control to
change charging current and steady the voltages of the rechargeable
battery 20 after charging is completed. The above-mentioned
software control is related to change the voltage of the control
signals (AUXDAC).
[0023] FIG. 4 depicts a charging circuit diagram of the
feedback-type charging circuit in the present invention. The
feedback-type charging circuit 14 comprises a charging current
control circuit 141, a first detecting circuit 142, a second
detecting circuit 143 and a voltage transforming circuit 144. An
external direct current (DC IN) is input to the input terminals of
the charging current control circuit 141 and the charging current
control circuit 141 receives control signals (AUXDAC) output from
the microprocessor 10 for controlling the charging current value
(I).
[0024] The first detecting circuit 142 is connected to a connecting
point V_CHG of the charging current control circuit 141 and the
connecting point V_CHG feeds back a signal AI00 to the
microprocessor 10 through a voltage divider network composed of
resistors R7, R8. By identifying the voltage magnitude of the
feedback signals AI00 and the following formula, charging current
value I may be calculated.
V.sub.--CHG=(DC IN)-I (charging current)*R4
AI00=V.sub.--CHG*(R8)/(R7+R8)
[0025] where the resistor values and DC IN are already known. After
the AI00 is detected by the first detecting value, V_CHG may be
calculated first, and charging current value (I) will be obtained
by using V_CHG value. It is concluded that AI00 and charging
current (I) are related to each other.
[0026] The second detecting circuit 143 is connected to a
connecting point VBAT of the charging current control circuit 141;
the connecting point VBAT is connected to a rechargeable battery 20
(not shown) and it feeds back a signal AI01 to the microprocessor
10 through a voltage divider network composed of resistors R9, R10.
By identifying the voltage magnitude of the feedback signals AI01,
a voltage value of the rechargeable battery may be obtained by the
microprocessor 10.
[0027] When the charging action is operated in the present
invention, the second detecting circuit 143 will decide how much of
the charging current is used according to the voltage of the
rechargeable battery 20. The microprocessor 10 also can adjust the
desired current value via changing the control signals (AUXDAC)
after the first detecting circuit 142 detects the present current
value. The charging current control circuit 141 mainly comprises a
PMOS transistor, an NMOS transistor and other elements. Control
signals AUXDAC is input into the gate of the NMOS transistor Q2 to
control the drain current thereof. The voltage value of the
resistor R6 is changed with the drain current of the NMOS
transistor Q2. Thus, PMOS transistor Q1 changes the charging
current value (I) with the variation of the voltage of the resistor
R6.
[0028] The voltage transforming circuit 144 is connected to the
output terminals of the charging current control circuit 141 and it
transforms the voltage VBAT via a DC/DC transformer U1 into a
voltage for the microprocessor 10 and the communicating unit
12.
[0029] The present invention divides the charging procedure into
several states. There are four stages S1, S2, S3, S4 shown in FIG.
5 and FIG. 6. The S1 state uses a 10 mA charging current when the
voltage of the rechargeable battery 20 is smaller than 3V. The S2
state uses a 50 mA charging current when the voltage of the
rechargeable battery 20 is larger than 3V but smaller than 4V. The
S3 state uses a 0 mA charging current when the voltage of the
rechargeable battery 20 is larger than 4V. Finally, the S4 state
uses a 50 mA charging current when the voltage of the rechargeable
battery 20 is smaller than 3.8V.
[0030] During the time period 0-T1, the voltage of the rechargeable
battery 20 is smaller than 3V and charged as S1 state; during the
time period T1-T2, the voltage of the rechargeable battery 20 is
larger than 3V and charged as the S2 state. During the time period
T2-T3, the voltage of the rechargeable battery 20 is larger than 4V
and charged as the S3 state. During the time period T3-T4, the
voltage of the rechargeable battery 20 is smaller than 3.8V and is
charged as the S4 state. Finally, S3 and S4 state will be switched
alternatively to maintain the voltage of the rechargeable battery
20 at nearly 4V. Additionally, unplugging the input power source
(DC IN) plug will terminate the charging function and return to
normal mode.
[0031] The present invention replaces prior art charging IC with
feedback-type charging circuit 14 and includes software control
provided by the microprocessor 10 for changing the charging current
of the charging current control circuit 141. Integrating the
feedback circuit of the first detecting circuit 142 and the second
detecting circuit 143 can make more precise adjustments for the
charging currents and the voltage of the rechargeable battery 20 is
also kept in a stable range.
[0032] On another aspect, the present invention integrates a buzzer
22, and it is operated depending on the operation states, such as,
for example, power on/off, incoming call or battery out of use, of
the wireless earphone.
[0033] Therefore, the wireless earphone of the present invention
includes following advantages:
[0034] 1. reducing production costs;
[0035] 2. providing a precise charging function by the design of
feedback-type charging circuit; and
[0036] 3. enlarging output voice of a speaker by a built-in buzzer
and using different tones of the buzzer for different states of the
wireless earphone.
[0037] Although the present invention has been described with
reference to the preferred embodiment therefore, it will be
understood that the invention is not limited to the details
thereof. Various substitutions and modifications have suggested in
the foregoing description, and other will occur to those of
ordinary skill in the art. Therefore, all such substitutions and
modifications are intended to be embrace within the scope of the
invention as defined in the appended claims.
* * * * *